First view of Vista comes with $500 million marketing blitz: new operating system designed to better manage media.

THE Vista circus came to town last week. Local business reps flocked to the Los Angeles Convention Center to get a look as Microsoft Corp. rolled out its Windows Vista software. The new computer operating system aims to better manage the explosion of digital media and protect users from the dangers of the Internet.

The world's biggest software maker marked the launch of its first all-new Windows operating system in five years with a $500 million marketing blitz, including commercials featuring basketball star Lebron James and appearances by Microsoft cofounder Bill Gates on morning and late-night chat shows. In all, retailers in 70 countries were targeted.

"This is our largest launch ever," said Microsoft's Southern California General Manager Donna Armstrong. She called Vista the most important release of its dominant operating system since Windows 95 more than a decade ago, when shoppers waited for hours to be among the first to run the new software.

Windows runs on more than 95 percent of the world's computers, and the long-delayed new version is the first major release of a new Microsoft operating system since it introduced Windows XP in 2001.

Redmond, Wash.-based Microsoft has more than 3,500 business clients in the area, according to Armstrong, and employs about 200 workers at its downtown L.A. office. She maintained that the Vista launch would be "as big a deal as Windows 95."

In fact, consumer fanfare of that magnitude seems unlikely since Vista is not the dramatic leap in technology of past releases, but the new Windows could ultimately be just as successful.

The most obvious change is the new look. Vista's "Aero" interface uses 3-D graphics to create translucent windows that appear to float above the background screen. Other changes include a new multimedia platform for digital video, music and pictures.

In the fast year of its release, Vista, which required a $6 billion investment from Microsoft, will be installed on more than 100 million PCs worldwide, according to research reports.

But because only about 15 percent of existing computers have memory and graphics cards powerful enough to run premium versions of Vista, most users will have to buy a whole new computer if they want to upgrade.